In solving engineering problems, it is important that the solver should imagine the rational sequence of his actions. TRIZ has elaborated such a scheme - the Algorithm of Inventive Problem Solving (ARIZ) -, which ensures a distinct problem-solving scheme [1, 2].
ARIZ is a powerful tool that, with efficient use, assures solving of rather difficult problems. However, the ARIZ structure looks too rigid and complex, which requires a lengthy preliminary training. ARIZ is good as a tool for solving complex acute contradictions, which are comparatively rare in practice. In solving most problems, the use of ARIZ may be compared with "breaking a butterfly upon the wheel". Needed is a simple even if less efficient problem-solving procedure.

At present, several such simplified schemes of problem solving are available in the world. For instance, USIT proposed at Ford [3] or ASIT [4]. These methodologies are simple in use but they are not efficient enough because they only employ separate TRIZ tools and not always in their entirety.
If this problem-solving structure is rejected, the problem solving with the aid of TRIZ tools has a random character []. That is, the solver applies that of the TRIZ tools, in terms of which the problem condition is formulated. For instance, if the problem condition implies some technical contradiction, then the solver will first of all seek for a principle for solving that contradiction. If the problem condition is described through the interaction of two or more objects, standards and effects are used. Such an approach allows solving the problem but is inconvenient for training because the information is distributed over several TRIZ sections. In addition it is not quite clear when and where specific TRIZ tools should be used. So far, a considerable number of TRIZ tools have accumulated and sometimes each of them is considered to be all-sufficient. Such an approach reduces abruptly the TRIZ efficiency.

To increase the efficiency of TRIZ tools, we have used our multiyear experience in solving real problems to elaborate the scheme of solving a singular problem identified in an initial situation [5]. The scheme corresponds to the main stages of inventive problem solving proposed by H.Altshuller [6] and envisages actions to be performed not with real objects but with their models. The problem models are arranged in the order of increasing degree of generality. At the maximal level of generality, a transfer from the problem model to the solving model occurs. Then the degree of generality of the solving model reduces sequentially and a transfer to the object solution takes place.

The problem-solving structure is explained by the "Christmas Tree" diagram (Fig. 1). This diagram now serves as a basis for the on-line course TRIZtrainer used for training the SAMSUNG employees.


Fig. 1. "Christmas Tree" diagram.

What place is assigned to the TRIZ tools in this diagram?
The problem-solving process illustrated by the diagram includes the following transfers:

a. Transfer from the initial problem to its concept model.
Under this transfer, the skeleton is identified in the problem and the problem is freed from unnecessary details. It is necessary to determine the conflicting objects and the peculiarities of their interaction in time and in space, as well as the ideal final result for the situation under consideration.
In the first instance, the multi-screen scheme and the laws of engineering systems evolution [7] are used for determining the system's structure. To determine the system's functions, it is useful to make a functional analysis [8]. Used are also the notions of operational zone and operational time and determined are possible resources [10]. To obtain a range mark for problem solving, it is necessary to determine the ideal final result [1,2].

b. Constructing a technical contradiction.
To construct a technical contradiction, it is necessary to determine an ordinary, traditional method for improving the desired parameter characterizing the performance of the main useful function. This may be done by any method - by using engineering experience, available knowledge bases and by seeking for analogies with previously solved problems. It is appropriate here to use the methods that preceded TRIZ, such as brainstorming, method of focal objects, empathy and the like [9]. First of all it is necessary to find a principal solution that provides for a normal functioning of the system. As a rule, this solution cannot satisfy the solver.
Then it is necessary to check which of the system's parameters is worsened inadmissibly when the found solution is realized and to apply the rules of constructing a technical contradiction [10] formulated by H.Altshuller.

c. Resolving a technical contradiction.
In accordance with the Table of resolving contradictions [11], it is necessary to seek for intermediate concepts of problem solving by using available resource.

d. Constructing an abstract model of a problem.
An abstract model of a problem may be constructed by any convenient method in accordance with the model constructing rules. For instance, by using object modeling or the little creatures modeling method [12].
The most convenient method of constructing an abstract model is using the rules of su-field analysis and constructing a scheme of interaction of elements in the form of a su-field model [13]. All the objects participating in the concept model are replaced with abstract "substances" and the forces and interactions are replaced with corresponding "fields" that characterize the interaction between the objects.
In some cases, the model may be described through "subject - action - object" [14].

e. Constructing an abstract model of solution.
A solution model is constructed by transforming an abstract model of solution with the aid of the same tools as those used for constructing the problem model. In addition one may use analogies with the previously solved problems and trimming - removal of a problematic element from the problem model [7].

f. Determining the requirements for an X-element.
Preliminary description of an X-element that is necessary for the search for a real object with the use of available resources may be made in the form of a list or table. It is convenient to describe an X-element according to the scheme "Element - Element Feature - Feature Value" [15].

g. Constructing a physical contradiction.
To construct a physical contradiction, it is necessary to set mutually exclusive or contrary (in physical terms) requirements for the X-element or its part [16].

i. Resolving a physical contradiction.
This contradiction is resolved with the aid of some comparatively simple rules [17].

j. Constructing a concept of intermediate solution.
After constructing any abstract solution, it is necessary to pass to a concept solution. In this case, the most important thing is to see the possibility of using an available resource in an uncommon way. To do this, it is necessary to obey the rules of choosing and using the resources [18]. Used may be also other information that facilitates the choice of resources, for instance the effect index [19]. Besides, it would be useful to have a developed creative imagination and to know the rules of overcoming the psychological inertia [20].

k. Transfer to an object intermediate solution.
Transfer to a more specific object solution is performed with the aid of experiments [21]. They may be both special methodologies allowing for complex multifactor experiments and a simple mental experiment and expert evaluation of this problem by specialists. Everything depends on the ratio between the cost of the experimental check and the cost of errors in problem solving.

l. Constructing a final solution.
To construct a final solution, it is convenient to use the rules of combining alternative and competing systems [22]. The final solution is based, or it is better to say, is designed on the basis of one of the intermediate solutions, into which objects, materials and separate properties of other intermediate solutions are introduced. Before constructing a final solution, it is necessary to check the intermediate solutions for compliance with the lines of engineering systems evolution and to add the missed steps [23].



The proposed problem-solving scheme with the indication of the places for using the classical TRIZ tools may be successfully used for self-education and as an aid in problem solving.

The author is grateful to V.Lenyashin for assistance in writing this article.

References:
1. G.Altshuller: 1999, The innovation algorithm. Worchester, Massachusetts: Technical Innovation Center. ISBN 0964074044.
www.amazon.com

2. Severine Gahide. Smart Garment For Firefighters.
http://www.triz-journal.com/archives/1999/06/d/index.htm

3. Unified Structured Inventive Thinking.
http://ic.net/~ntelleck/ProblemStmnt.html

4. Roni Horowitz. From TRIZ to ASIT in 4 Steps.
http://www.triz-journal.com/archives/2001/08/c/index.htm

5. N. Shpakovsky, V. Lenjashin, Hyo June Kim. Structural Scheme For Solving a Problem Using TRIZ.
http://gnrtr.com/tools/en/a01.html

6. Г.Альтшуллер. Process of Invention Problem Solving. Main stages and tools.
http://www.trizminsk.org/c/126002.htm (in Russian)

7. Darrell Mann System Operator Tutorial 1) 9-Windows On The World.
http://www.triz-journal.com/archives/2001/09/c/index.html

8. James F. Kowalick. Tutorial: Use OF Functional Analysis and Pruning, with TRIZ and ARIZ, to Solve "Impossible - To - Solve" Problems.
http://www.triz-journal.com/archives/1996/12/d/index.html

9. Yoshiki Nakamura. The effective use of TRIZ with Brainstorming.
http://www.triz-journal.com/archives/2001/02/e/index.htm

10. Noel Leon-Rovira and Ing. Humberto Aguayo. A new Model of the Conceptual Design Process using QFD/FA/TRIZ.
http://www.triz-journal.com/archives/1998/07/d/index.htm

11. G.Altshuller: 1997, 40 PRINCIPLES: TRIZ Keys to Technical Innovation. Worchester, Massachusetts: Technical Innovation Center. ISBN 0964074036/
www.amazon.com

12. G.Altshuller: 1996, And Suddenly the Inventor Appeared: TRIZ, the Theory of Inventive Problem Solving. Worchester, Massachusetts: Technical Innovation Center. ISBN 0-9640740-2-8.
www.amazon.com

13. John Terninko, Ellen Domb, Joe Miller.The Seventy-six Standard Solutions, with Examples - Class 5.
http://www.triz-journal.com/archives/2000/07/b/index.htm

14. Tsourikov, Valery and all. US Patent 20020116176 Semantic answering system and method.

15. Sebastien Dubois, Nikolay Khomenko, Pilippe Lutz, Ronald De Guio. "Problem formulation - A Key Step in the process of Resolution of Inventive Problem". World Conference "TRIZ future 2001".

16. Semyon D. Savransky: Lesson 4 Contradictions.
http://www.triz-journal.com/archives/1999/11/b/index.htm

17. Semyon D. Savransky: ENGINEERING OF CREATIVITY: Introduction to TRIZ Methodology of Inventive Problem Solving. 2000. ISBN 0849322553
www.amazon.com

18. Z. Roizen. Specifics of using of the resources for problem solving and solutions developing. (paper for 4-th seminar in Petrozavodsk-87).

19. Gregory Frenklach Classifying the Technical Effects.
http://www.triz-journal.com/archives/1998/03/a/index.htm

20. Martin Hyatt. An Overview of Synoptics and the Six Challenges of Creativity.
http://www.triz-journal.com/archives/2002/10/f/index.htm

21. John Hsing Conflict Resolution Using TRIZ and Design of Experiment (DOE).
http://www.triz-journal.com/archives/2001/05/b/index.htm

22. Litvin S. S., Gerassimov V. M. "Development of alternative technical systems by incorporating them into supersystem". Proc. ICED 91 Zurich, Vol. 1, 1991, pp 42-45.

23. Victor R. Fey, Eugene I. Rivin. Guided Technology Evolution (TRIZ Technology Forecasting).
http://www.triz-journal.com/archives/1999/01/c/index.htm

Additional information:
N. Khomenko, D. Kucharavy. LIST OF TRIZ-BOOKS
http://www.trizminsk.org/eng/book.htm